Saia-Burgess Controls AG
Manual I/O-modules for PCD1 │ PCD2 series │ Document 27-600 – Release ENG09 │ 2019-05-01
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I/O modules PCD1|PCD2
PCD2.W2x0
5
Temperature measurement with Pt 1000
In the temperature range – 50 °C to + 400 °C, the following formulae can be used for
working to an accuracy of ± 1 % (± 1.5 °C). Repeating accuracy is significantly higher.
T=temperature in ° C
DV = digital value (0
…
1023)
Example 1:
digital value DV = 562
temperature T in ° C ?
DV=digital value (0 … 1023)
T = temperature in ° C
Example 2:
preset temperature T = –10 °C
corresponding digital value DV ?
Resistance measurement up to 2.5 kΩ
Special temperature sensors or any other resistances up to 2.5 kΩ can be con
-
nected to the PCD2.W220. The digital value can be calculated as follows:
where 0 ≤ DV ≤ 1023 and R=the resistance to be measured in Ω.
DV=
4092 • R
(7500 + R)
T[° C]=
– 261,8
DV
2.08 – (0.509 • 10-³ • DV)
T[° C]=
– 261,8
562
2.08 – (0.509 • 10-³ • 562)
= 51.5 °C
DV=
2.08 • (261.8 + T)
1 + (0.509 • 10-³ • (261.8 + T))
DV=
2.08 • (261.8 – 10)
1 + (0.509 • 10-³ • (261.8 – 10))
= 464